Xenograft Studies: 101

Perhaps you are currently embarking upon a medical degree, intending to move into the fascinating yet challenging world of drug research, development, and discovery.

Alternatively, maybe you are already a qualified medical professional who is looking to move into the area from an entirely different specialism. Perhaps you are a researcher interested in the subject matter. Either way, here are the basics concerning xenograft studies, specifically patient-derived xenografts. 

The Difference Between PDX & CDX

Animal-based models are at the heart of drug discovery and development, which are used to accurately understand the impact and effects of potentially new and innovative drugs.

In the field of oncology specifically, since the early days of developing new drugs to treat patients with all forms of cancer, such models have always been of the CDX variety. CDX (Cell Line Xenografts) utilize the specific tumor cells taken from the tissues of patients and are then adapted and developed to be able to grow independently on plastics and other manmade materials.

However, PDX (Patient-Derived Xenografts) takes a sample of the infected tissue and instead implants it directly and immediately into a mouse or rat. Should the implant be successful and achieve what is to be considered reasonable rates of growth, they are then implanted into further mice and then become a PDX. 

The Two Main Functions of PDX

Although the invention and subsequent successful PDX models provide numerous advantages for medical and drug researchers, there are certainly two overarching benefits. The first primary function of PDX is as an individual, specific model which can be used to study the responses of certain tumors (as long as the PDX model you are using possess matching genetic features). 

The second most impressive function is in the context of studies of populations, for everything from the identification of resistance mechanisms, biomarker analysis, preclinical screenings of drugs, and identification of sensitivity mechanisms. 

The Information Gleaned From PDX

One of the huge advantages to medical researchers and those professionals working in drug discovery, design and development is to do with the impressive amount of model and patient information PDX provides.

The background data received from a successfully implanted PDX through scientific studies conducted using a humanized SRG rat, amongst a host of others, the following:

• Any previous treatments 
• Ethnicity
• Grade and stage of the disease
• Pathology diagnosis
• Smoking habit
• Age
• Site of Biopsy 

Key Characteristics of PDX Models

Finally, PDX models have been so exponentially successful in the journey of drug development and discovery because PDX are an effective and impressively accurate way of predicting the efficacy of preclinical development. 

As PDX models are taken directly from the tumor of the patient and are not manufactured as is the case with CDX, they much more accurately represent the real-life variables. 

Working in drug discovery and development is not only a specialist, a fascinating area of medicine and healthcare. Still, it places you at the front of innovations that can help save hundreds, thousands, and even millions of lives in the future.